The decision entitles 70,000 surviving emergency service workers and other survivors to free care.
The National Institute for Occupational Safety announced the change on the eve of the attacks' 11th anniversary.
Some 1,000 deaths have been linked to illnesses caused by toxic dust issuing from wreckage at Ground Zero.
Researchers found only 21 out of 93 countries where malaria is common have received enough money to implement effective control measures.
African countries have seen the biggest funding increases but billions are still needed elsewhere, the experts say in the Lancet medical journal.
The Roll Back Malaria Campaign warned $4.9bn .
